Related Experiment Video
Updated: May 31, 2026
Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System
Published on: May 5, 2018
Does diurnal rhythm have an impact on fetal biophysical profile?
Enis Ozkaya1, Eralp Baser, Mehmet Cinar
1Department of Obstetrics and Gynecology, Dr. Sami Ulus Women's and Children's Health, Ankara, Turkey.
Objectives:
To investigate whether parameters in fetal biophysical profile (BPP) testing exhibit a diurnal rhythm and to discuss the probable factors associated with these variables.
Methods:
Thirty healthy primigravid patients carrying pregnancies between 35 and 40 completed weeks were enrolled for the study. Fetal BPP testing was performed for each patient both in the early morning (08:00-10:00 am) and in the late evening (08:00-10:00 pm), and the scoring parameters were compared between morning and evening tests.
Results:
BPP scores in the evening were significantly higher than that in the morning (p < 0.05). Deepest vertical amniotic pocket measurements and fetal breathing absence in the morning mostly contributed to this variation (p < 0.001). Fetal movement counts were also significantly lower in the morning tests (p < 0.001).
Conclusions:
The parameters of BPP exhibit circadian variations in healthy fetuses, which may be associated with many factors such as fetomaternal hormones. It is essential for the clinician to be aware of these changes when interpreting the results, as interventions based on false-positive results may have deleterious effects on both the mother and her fetus.
Related Concept Videos
01:14Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
01:15Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement: